<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .item-container{
            position: relative;
            float: left;
            left: 50%;
            border: solid 1px red;
        }

        .item{
        }

        .item-1{
            position: relative;
            left: -50%;
            background-color: palegreen;
        }
    </style>
</head>
<body>
<div class="item-container">
    <div class="item item-1">this is my page</div>
</div>
</body>
</html>
